Enlarge / Here is a comparison of the safe area in landscape mode on the iPhone 8 and on the iPhone X. (credit: Apple) Today, Apple emailed iOS developers to explore new features in iOS 11 like ARKit. In that email, the company also announced that all new apps submitted from April 2018 onward must be built with the iOS 11 SDK and must support the iPhone X's new display. This was Apple's complete message to developers on the subject: iOS 11 has brought innovative features and the redesigned App Store to hundreds of millions of customers around the world.